When circuit boards, or an electronic part, such as an IC chip, and a circuit board are electrically connected, anisotropic conductive adhesives in which conductive particles are dispersed are used. These adhesives are located between opposed electrodes, and the electrodes are connected by heating and pressurization. Then, conductivity in the direction of pressurization is provided and thereby electrical connection and fixing are provided.
As the above conductive particles, for example, the use of coated conductive particles obtained by coating the surfaces of conductive particles with an insulator is proposed.
For example, the following Patent Document 1 proposes a method using coated particles obtained by substantially covering, with a thermoplastic insulating layer, particles obtained by using a polymer as a core material and forming a conductive metal thin layer on its surface. Also, the following Patent Document 2 proposes a method using microcapsule-type conductive particles obtained by forming on the surfaces of resin balls a plating layer obtained by metal plating, and uniformly coating the surface of the above plating layer with an insulating resin layer. Also, the following Patent Document 3 proposes a method using insulating coated conductive particles coated with an insulating resin insoluble in an insulating adhesive. Also, the following Patent Document 4 proposes a method using coated conductive fine particles obtained by chemically bonding coating insulating particles to particles having surfaces comprising a conductive metal via a functional group having bonding properties to the above conductive metal to form a single coating layer.    Patent Document 1: Japanese Patent Laid-Open No. 08-249922    Patent Document 2: Japanese Patent Laid-Open No. 05-70750    Patent Document 3: Japanese Patent Laid-Open No. 11-241054    Patent Document 4: International Publication No. WO2003/025955